Premier Foods blamed subdued grocery retail trading, a later Easter and milder weather for lower sales of its key brands and said trading was likely to stay tough for the rest of the year.Premier, which makes products such as Mr Kipling cakes, Ambrosia custard and Sharwood's curry sauces, said sales of its "power brands" fell 3.5% to £123.7m as expected and total sales dropped 6.2% to £186.3m in the three months to March 31st.Demand for its Loyd Grossman sauces rose in the quarter, supported by new lasagne sauce pouches, but Sharwood's sales fell due to a particularly competitive market.Sales of support brands fell 10.4% as Easter fell in the company's second quarter this year, hitting sales of Cadbury cakes.The group is keeping a 49% stake in its Hovis bread business, which it is putting in a planned Hovis Holdings joint venture with the Gores Group expected to complete on April 26th.It is reducing suppliers as part of a drive to cut business costs and complexity and said the number of suppliers had fallen by more than 38% since the start of 2013 to 2,040, putting it on track to meet a target of 1,660 by the end of 2014.Chief Executive Gavin Darby said Premier's expectations for the full year had not changed."While trading conditions are expected to remain challenging for the remainder of the year, we have a strong programme of new product launches and consumer marketing planned for the second half," he said.Shares fell 2p or 3.15% to 61.5p in early trading in London.PW